Intestinal Biopsies for the Evaluation of Environmental Enteropathy and Environmental Enteric Dysfunction

Abstract

Environmental enteric dysfunction (EED) is a syndrome characterised by impairments of digestion and absorption and intestinal barrier failure in people living in insanitary or tropical environments. There is substantial evidence that it contributes to impaired linear growth of millions of children in low- and middle-income countries, to slowed neurocognitive development, and to diminished responses to oral vaccines. It represents the functional consequences of environmental enteropathy, an asymptomatic inflammatory disorder of the mucosa, and there is considerable overlap with the enteropathy observed in severe clinical malnutrition. The majority of studies of EED have employed functional tests based on lactulose permeation to define the presence of abnormal leak in the gut. However, where intestinal biopsies can safely be collected the opportunity then arises to study the underlying enteropathy in cellular and molecular detail, as well as to measure important functional elements such as enzyme expression. The purpose of this narrative review is to summarise the current understanding of environmental enteropathy (EE) obtained from small intestinal biopsies, and prospects for future work. We review histology, electron microscopy, transcription and protein expression, physiological measures, and the microbiome. We conclude that while non-invasive biomarkers of enteropathy and intestinal dysfunction permit large scale studies of unquestionable value, intestinal biopsies are still required to investigate pathophysiology in depth.

Lack of Associations between Environmental Exposures and Environmental Enteric Dysfunction among 18-Month-Old Children in Rural Malawi

“…Environmental enteric dysfunction (EED) is a common condition among children in low-income settings. It is characterized by increased intestinal permeability, intestinal inflammation, and impaired barrier function [ 1 , 2 ]. EED typically starts in infancy and continues into adulthood [ 1 , 3 ].…”

Potential determinants of low circulating glucagon‐like peptide 2 concentrations in Zambian children with non‐responsive stunting

“…Among the secretory cell types, Paneth and goblet cell depletion has been shown to be a prominent feature of environmental enteropathy, but less is known about changes in enteroendocrine and tuft cells in enteropathy and malnutrition (Hodges et al., 2021 ). Goblet, Paneth and endocrine cell loss has also been shown in an adult patient with autoimmune enteropathy (Al Khalidi et al., 2006 ) as well as in paediatric patients with autoimmune polyendocrine–candidiasis–ectodermal dystrophy (APECED).…”

ApoE Mimetic Peptides to Improve the Vicious Cycle of Malnutrition and Enteric Infections by Targeting the Intestinal and Blood-Brain Barriers

“…Less invasive biomarkers are of utmost importance for the early diagnosis of EED and its appropriate management. The recent use of new technologies, such as transcriptomic analysis, are already shedding light on novel underlying mechanisms of the disease [35].…”